xref: /netbsd-src/sys/arch/sparc/dev/sw.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: sw.c,v 1.14 2003/12/04 12:42:54 keihan Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Adam Glass, David Jones, Gordon W. Ross, and Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * This file contains only the machine-dependent parts of the
41  * Sun4 SCSI driver.  (Autoconfig stuff and DMA functions.)
42  * The machine-independent parts are in ncr5380sbc.c
43  *
44  * Supported hardware includes:
45  * Sun "SCSI Weird" on OBIO (sw: Sun 4/100-series)
46  * Sun SCSI-3 on VME (si: Sun 4/200-series, others)
47  *
48  * The VME variant has a bit to enable or disable the DMA engine,
49  * but that bit also gates the interrupt line from the NCR5380!
50  * Therefore, in order to get any interrupt from the 5380, (i.e.
51  * for reselect) one must clear the DMA engine transfer count and
52  * then enable DMA.  This has the further complication that you
53  * CAN NOT touch the NCR5380 while the DMA enable bit is set, so
54  * we have to turn DMA back off before we even look at the 5380.
55  *
56  * What wonderfully whacky hardware this is!
57  *
58  * David Jones wrote the initial version of this module for NetBSD/sun3,
59  * which included support for the VME adapter only. (no reselection).
60  *
61  * Gordon Ross added support for the Sun 3 OBIO adapter, and re-worked
62  * both the VME and OBIO code to support disconnect/reselect.
63  * (Required figuring out the hardware "features" noted above.)
64  *
65  * The autoconfiguration boilerplate came from Adam Glass.
66  *
67  * Jason R. Thorpe ported the autoconfiguration and VME portions to
68  * NetBSD/sparc, and added initial support for the 4/100 "SCSI Weird",
69  * a wacky OBIO variant of the VME SCSI-3.  Many thanks to Chuck Cranor
70  * for lots of helpful tips and suggestions.  Thanks also to Paul Kranenburg
71  * and Chris Torek for bits of insight needed along the way.  Thanks to
72  * David Gilbert and Andrew Gillham who risked filesystem life-and-limb
73  * for the sake of testing.  Andrew Gillham helped work out the bugs
74  * the 4/100 DMA code.
75  */
76 
77 /*
78  * NOTE: support for the 4/100 "SCSI Weird" is not complete!  DMA
79  * works, but interrupts (and, thus, reselection) don't.  I don't know
80  * why, and I don't have a machine to test this on further.
81  *
82  * DMA, DMA completion interrupts, and reselection work fine on my
83  * 4/260 with modern SCSI-II disks attached.  I've had reports of
84  * reselection failing on Sun Shoebox-type configurations where
85  * there are multiple non-SCSI devices behind Emulex or Adaptec
86  * bridges.  These devices pre-date the SCSI-I spec, and might not
87  * bahve the way the 5380 code expects.  For this reason, only
88  * DMA is enabled by default in this driver.
89  *
90  *	Jason R. Thorpe <thorpej@NetBSD.org>
91  *	December 8, 1995
92  */
93 
94 #include <sys/cdefs.h>
95 __KERNEL_RCSID(0, "$NetBSD: sw.c,v 1.14 2003/12/04 12:42:54 keihan Exp $");
96 
97 #include "opt_ddb.h"
98 
99 #include <sys/types.h>
100 #include <sys/param.h>
101 #include <sys/systm.h>
102 #include <sys/kernel.h>
103 #include <sys/malloc.h>
104 #include <sys/errno.h>
105 #include <sys/device.h>
106 #include <sys/buf.h>
107 
108 #include <machine/bus.h>
109 #include <machine/intr.h>
110 #include <machine/autoconf.h>
111 
112 #include <dev/scsipi/scsi_all.h>
113 #include <dev/scsipi/scsipi_all.h>
114 #include <dev/scsipi/scsipi_debug.h>
115 #include <dev/scsipi/scsiconf.h>
116 
117 #ifndef DDB
118 #define	Debugger()
119 #endif
120 
121 #ifndef DEBUG
122 #define DEBUG XXX
123 #endif
124 
125 #define COUNT_SW_LEFTOVERS	XXX	/* See sw DMA completion code */
126 
127 #include <dev/ic/ncr5380reg.h>
128 #include <dev/ic/ncr5380var.h>
129 
130 #include <sparc/dev/swreg.h>
131 
132 /*
133  * Transfers smaller than this are done using PIO
134  * (on assumption they're not worth DMA overhead)
135  */
136 #define	MIN_DMA_LEN 128
137 
138 /*
139  * Transfers lager than 65535 bytes need to be split-up.
140  * (Some of the FIFO logic has only 16 bits counters.)
141  * Make the size an integer multiple of the page size
142  * to avoid buf/cluster remap problems.  (paranoid?)
143  */
144 #define	MAX_DMA_LEN 0xE000
145 
146 #ifdef	DEBUG
147 int sw_debug = 0;
148 #endif
149 
150 /*
151  * This structure is used to keep track of mapped DMA requests.
152  */
153 struct sw_dma_handle {
154 	int 		dh_flags;
155 #define	SIDH_BUSY	0x01		/* This DH is in use */
156 #define	SIDH_OUT	0x02		/* DMA does data out (write) */
157 	u_char		*dh_addr;	/* KVA of start of buffer */
158 	int 		dh_maplen;	/* Original data length */
159 	long		dh_startingpa;	/* PA of buffer; for "sw" */
160 	bus_dmamap_t	dh_dmamap;
161 #define dh_dvma	dh_dmamap->dm_segs[0].ds_addr /* VA of buffer in DVMA space */
162 };
163 
164 /*
165  * The first structure member has to be the ncr5380_softc
166  * so we can just cast to go back and fourth between them.
167  */
168 struct sw_softc {
169 	struct ncr5380_softc	ncr_sc;
170 	bus_space_tag_t		sc_bustag;	/* bus tags */
171 	bus_dma_tag_t		sc_dmatag;
172 
173 	struct sw_dma_handle *sc_dma;
174 	int		sc_xlen;	/* length of current DMA segment. */
175 	int		sc_options;	/* options for this instance. */
176 };
177 
178 /*
179  * Options.  By default, DMA is enabled and DMA completion interrupts
180  * and reselect are disabled.  You may enable additional features
181  * the `flags' directive in your kernel's configuration file.
182  *
183  * Alternatively, you can patch your kernel with DDB or some other
184  * mechanism.  The sc_options member of the softc is OR'd with
185  * the value in sw_options.
186  *
187  * On the "sw", interrupts (and thus) reselection don't work, so they're
188  * disabled by default.  DMA is still a little dangerous, too.
189  *
190  * Note, there's a separate sw_options to make life easier.
191  */
192 #define	SW_ENABLE_DMA	0x01	/* Use DMA (maybe polled) */
193 #define	SW_DMA_INTR	0x02	/* DMA completion interrupts */
194 #define	SW_DO_RESELECT	0x04	/* Allow disconnect/reselect */
195 #define	SW_OPTIONS_MASK	(SW_ENABLE_DMA|SW_DMA_INTR|SW_DO_RESELECT)
196 #define SW_OPTIONS_BITS	"\10\3RESELECT\2DMA_INTR\1DMA"
197 int sw_options = SW_ENABLE_DMA;
198 
199 static int	sw_match __P((struct device *, struct cfdata *, void *));
200 static void	sw_attach __P((struct device *, struct device *, void *));
201 static int	sw_intr __P((void *));
202 static void	sw_reset_adapter __P((struct ncr5380_softc *));
203 static void	sw_minphys __P((struct buf *));
204 
205 void	sw_dma_alloc __P((struct ncr5380_softc *));
206 void	sw_dma_free __P((struct ncr5380_softc *));
207 void	sw_dma_poll __P((struct ncr5380_softc *));
208 
209 void	sw_dma_setup __P((struct ncr5380_softc *));
210 void	sw_dma_start __P((struct ncr5380_softc *));
211 void	sw_dma_eop __P((struct ncr5380_softc *));
212 void	sw_dma_stop __P((struct ncr5380_softc *));
213 
214 void	sw_intr_on __P((struct ncr5380_softc *));
215 void	sw_intr_off __P((struct ncr5380_softc *));
216 
217 /* Shorthand bus space access */
218 #define SWREG_READ(sc, index) \
219 	bus_space_read_4((sc)->sc_regt, (sc)->sc_regh, index)
220 #define SWREG_WRITE(sc, index, v) \
221 	bus_space_write_4((sc)->sc_regt, (sc)->sc_regh, index, v)
222 
223 
224 /* The Sun "SCSI Weird" 4/100 obio controller. */
225 CFATTACH_DECL(sw, sizeof(struct sw_softc),
226     sw_match, sw_attach, NULL, NULL);
227 
228 static int
229 sw_match(parent, cf, aux)
230 	struct device	*parent;
231 	struct cfdata *cf;
232 	void *aux;
233 {
234 	union obio_attach_args *uoba = aux;
235 	struct obio4_attach_args *oba;
236 
237 	/* Nothing but a Sun 4/100 is going to have these devices. */
238 	if (cpuinfo.cpu_type != CPUTYP_4_100)
239 		return (0);
240 
241 	if (uoba->uoba_isobio4 == 0)
242 		return (0);
243 
244 	/* Make sure there is something there... */
245 	oba = &uoba->uoba_oba4;
246 	return (bus_space_probe(oba->oba_bustag, oba->oba_paddr,
247 				1,	/* probe size */
248 				1,	/* offset */
249 				0,	/* flags */
250 				NULL, NULL));
251 }
252 
253 static void
254 sw_attach(parent, self, aux)
255 	struct device	*parent, *self;
256 	void		*aux;
257 {
258 	struct sw_softc *sc = (struct sw_softc *) self;
259 	struct ncr5380_softc *ncr_sc = &sc->ncr_sc;
260 	union obio_attach_args *uoba = aux;
261 	struct obio4_attach_args *oba = &uoba->uoba_oba4;
262 	bus_space_handle_t bh;
263 	char bits[64];
264 	int i;
265 
266 	sc->sc_dmatag = oba->oba_dmatag;
267 
268 	/* Map the controller registers. */
269 	if (bus_space_map(oba->oba_bustag, oba->oba_paddr,
270 			  SWREG_BANK_SZ,
271 			  BUS_SPACE_MAP_LINEAR,
272 			  &bh) != 0) {
273 		printf("%s: cannot map registers\n", self->dv_xname);
274 		return;
275 	}
276 
277 	ncr_sc->sc_regt = oba->oba_bustag;
278 	ncr_sc->sc_regh = bh;
279 
280 	sc->sc_options = sw_options;
281 
282 	ncr_sc->sc_dma_setup = sw_dma_setup;
283 	ncr_sc->sc_dma_start = sw_dma_start;
284 	ncr_sc->sc_dma_eop   = sw_dma_stop;
285 	ncr_sc->sc_dma_stop  = sw_dma_stop;
286 	ncr_sc->sc_intr_on   = sw_intr_on;
287 	ncr_sc->sc_intr_off  = sw_intr_off;
288 
289 	/*
290 	 * Establish interrupt channel.
291 	 * Default interrupt priority always is 3.  At least, that's
292 	 * what my board seems to be at.  --thorpej
293 	 */
294 	if (oba->oba_pri == -1)
295 		oba->oba_pri = 3;
296 
297 	(void)bus_intr_establish(oba->oba_bustag, oba->oba_pri, IPL_BIO,
298 				 sw_intr, sc);
299 
300 	printf(" pri %d\n", oba->oba_pri);
301 
302 
303 	/*
304 	 * Pull in the options flags.  Allow the user to completely
305 	 * override the default values.
306 	 */
307 	if ((ncr_sc->sc_dev.dv_cfdata->cf_flags & SW_OPTIONS_MASK) != 0)
308 		sc->sc_options =
309 		    (ncr_sc->sc_dev.dv_cfdata->cf_flags & SW_OPTIONS_MASK);
310 
311 	/*
312 	 * Initialize fields used by the MI code
313 	 */
314 
315 	/* NCR5380 register bank offsets */
316 	ncr_sc->sci_r0 = 0;
317 	ncr_sc->sci_r1 = 1;
318 	ncr_sc->sci_r2 = 2;
319 	ncr_sc->sci_r3 = 3;
320 	ncr_sc->sci_r4 = 4;
321 	ncr_sc->sci_r5 = 5;
322 	ncr_sc->sci_r6 = 6;
323 	ncr_sc->sci_r7 = 7;
324 
325 	ncr_sc->sc_rev = NCR_VARIANT_NCR5380;
326 
327 	/*
328 	 * MD function pointers used by the MI code.
329 	 */
330 	ncr_sc->sc_pio_out = ncr5380_pio_out;
331 	ncr_sc->sc_pio_in =  ncr5380_pio_in;
332 	ncr_sc->sc_dma_alloc = sw_dma_alloc;
333 	ncr_sc->sc_dma_free  = sw_dma_free;
334 	ncr_sc->sc_dma_poll  = sw_dma_poll;
335 
336 	ncr_sc->sc_flags = 0;
337 	if ((sc->sc_options & SW_DO_RESELECT) == 0)
338 		ncr_sc->sc_no_disconnect = 0xFF;
339 	if ((sc->sc_options & SW_DMA_INTR) == 0)
340 		ncr_sc->sc_flags |= NCR5380_FORCE_POLLING;
341 	ncr_sc->sc_min_dma_len = MIN_DMA_LEN;
342 
343 
344 	/*
345 	 * Allocate DMA handles.
346 	 */
347 	i = SCI_OPENINGS * sizeof(struct sw_dma_handle);
348 	sc->sc_dma = (struct sw_dma_handle *)malloc(i, M_DEVBUF, M_NOWAIT);
349 	if (sc->sc_dma == NULL)
350 		panic("sw: DMA handle malloc failed");
351 
352 	for (i = 0; i < SCI_OPENINGS; i++) {
353 		sc->sc_dma[i].dh_flags = 0;
354 
355 		/* Allocate a DMA handle */
356 		if (bus_dmamap_create(
357 				sc->sc_dmatag,	/* tag */
358 				MAXPHYS,	/* size */
359 				1,		/* nsegments */
360 				MAXPHYS,	/* maxsegsz */
361 				0,		/* boundary */
362 				BUS_DMA_NOWAIT,
363 				&sc->sc_dma[i].dh_dmamap) != 0) {
364 
365 			printf("%s: DMA buffer map create error\n",
366 				ncr_sc->sc_dev.dv_xname);
367 			return;
368 		}
369 	}
370 
371 	if (sc->sc_options) {
372 		printf("%s: options=%s\n", ncr_sc->sc_dev.dv_xname,
373 			bitmask_snprintf(sc->sc_options, SW_OPTIONS_BITS,
374 			    bits, sizeof(bits)));
375 	}
376 
377 	ncr_sc->sc_channel.chan_id = 7;
378 	ncr_sc->sc_adapter.adapt_minphys = sw_minphys;
379 
380 	/* Initialize sw board */
381 	sw_reset_adapter(ncr_sc);
382 
383 	/* Attach the ncr5380 chip driver */
384 	ncr5380_attach(ncr_sc);
385 }
386 
387 static void
388 sw_minphys(struct buf *bp)
389 {
390 	if (bp->b_bcount > MAX_DMA_LEN) {
391 #ifdef DEBUG
392 		if (sw_debug) {
393 			printf("sw_minphys len = 0x%x.\n", MAX_DMA_LEN);
394 			Debugger();
395 		}
396 #endif
397 		bp->b_bcount = MAX_DMA_LEN;
398 	}
399 	minphys(bp);
400 }
401 
402 #define CSR_WANT (SW_CSR_SBC_IP | SW_CSR_DMA_IP | \
403 	SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR )
404 
405 static int
406 sw_intr(void *arg)
407 {
408 	struct sw_softc *sc = arg;
409 	struct ncr5380_softc *ncr_sc = (struct ncr5380_softc *)arg;
410 	int dma_error, claimed;
411 	u_short csr;
412 
413 	claimed = 0;
414 	dma_error = 0;
415 
416 	/* SBC interrupt? DMA interrupt? */
417 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
418 
419 	NCR_TRACE("sw_intr: csr=0x%x\n", csr);
420 
421 	if (csr & SW_CSR_DMA_CONFLICT) {
422 		dma_error |= SW_CSR_DMA_CONFLICT;
423 		printf("sw_intr: DMA conflict\n");
424 	}
425 	if (csr & SW_CSR_DMA_BUS_ERR) {
426 		dma_error |= SW_CSR_DMA_BUS_ERR;
427 		printf("sw_intr: DMA bus error\n");
428 	}
429 	if (dma_error) {
430 		if (sc->ncr_sc.sc_state & NCR_DOINGDMA)
431 			sc->ncr_sc.sc_state |= NCR_ABORTING;
432 		/* Make sure we will call the main isr. */
433 		csr |= SW_CSR_DMA_IP;
434 	}
435 
436 	if (csr & (SW_CSR_SBC_IP | SW_CSR_DMA_IP)) {
437 		claimed = ncr5380_intr(&sc->ncr_sc);
438 #ifdef DEBUG
439 		if (!claimed) {
440 			printf("sw_intr: spurious from SBC\n");
441 			if (sw_debug & 4) {
442 				Debugger();	/* XXX */
443 			}
444 		}
445 #endif
446 	}
447 
448 	return (claimed);
449 }
450 
451 
452 static void
453 sw_reset_adapter(struct ncr5380_softc *ncr_sc)
454 {
455 
456 #ifdef	DEBUG
457 	if (sw_debug) {
458 		printf("sw_reset_adapter\n");
459 	}
460 #endif
461 
462 	/*
463 	 * The reset bits in the CSR are active low.
464 	 */
465 	SWREG_WRITE(ncr_sc, SWREG_CSR, 0);
466 	delay(10);
467 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES);
468 
469 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
470 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
471 	delay(10);
472 	SWREG_WRITE(ncr_sc, SWREG_CSR, SW_CSR_SCSI_RES | SW_CSR_INTR_EN);
473 
474 	SCI_CLR_INTR(ncr_sc);
475 }
476 
477 
478 /*****************************************************************
479  * Common functions for DMA
480  ****************************************************************/
481 
482 /*
483  * Allocate a DMA handle and put it in sc->sc_dma.  Prepare
484  * for DMA transfer.  On the Sun4, this means mapping the buffer
485  * into DVMA space.
486  */
487 void
488 sw_dma_alloc(ncr_sc)
489 	struct ncr5380_softc *ncr_sc;
490 {
491 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
492 	struct sci_req *sr = ncr_sc->sc_current;
493 	struct scsipi_xfer *xs = sr->sr_xs;
494 	struct sw_dma_handle *dh;
495 	int i, xlen;
496 	u_long addr;
497 
498 #ifdef DIAGNOSTIC
499 	if (sr->sr_dma_hand != NULL)
500 		panic("sw_dma_alloc: already have DMA handle");
501 #endif
502 
503 #if 1	/* XXX - Temporary */
504 	/* XXX - In case we think DMA is completely broken... */
505 	if ((sc->sc_options & SW_ENABLE_DMA) == 0)
506 		return;
507 #endif
508 
509 	addr = (u_long) ncr_sc->sc_dataptr;
510 	xlen = ncr_sc->sc_datalen;
511 
512 	/* If the DMA start addr is misaligned then do PIO */
513 	if ((addr & 1) || (xlen & 1)) {
514 		printf("sw_dma_alloc: misaligned.\n");
515 		return;
516 	}
517 
518 	/* Make sure our caller checked sc_min_dma_len. */
519 	if (xlen < MIN_DMA_LEN)
520 		panic("sw_dma_alloc: xlen=0x%x", xlen);
521 
522 	/* Find free DMA handle.  Guaranteed to find one since we have
523 	   as many DMA handles as the driver has processes. */
524 	for (i = 0; i < SCI_OPENINGS; i++) {
525 		if ((sc->sc_dma[i].dh_flags & SIDH_BUSY) == 0)
526 			goto found;
527 	}
528 	panic("sw: no free DMA handles.");
529 
530 found:
531 	dh = &sc->sc_dma[i];
532 	dh->dh_flags = SIDH_BUSY;
533 	dh->dh_addr = (u_char *)addr;
534 	dh->dh_maplen  = xlen;
535 
536 	/* Copy the "write" flag for convenience. */
537 	if ((xs->xs_control & XS_CTL_DATA_OUT) != 0)
538 		dh->dh_flags |= SIDH_OUT;
539 
540 	/*
541 	 * Double-map the buffer into DVMA space.  If we can't re-map
542 	 * the buffer, we print a warning and fall back to PIO mode.
543 	 *
544 	 * NOTE: it is not safe to sleep here!
545 	 */
546 	if (bus_dmamap_load(sc->sc_dmatag, dh->dh_dmamap,
547 			    (caddr_t)addr, xlen, NULL, BUS_DMA_NOWAIT) != 0) {
548 		/* Can't remap segment */
549 		printf("sw_dma_alloc: can't remap 0x%lx/0x%x, doing PIO\n",
550 			addr, dh->dh_maplen);
551 		dh->dh_flags = 0;
552 		return;
553 	}
554 	bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap, addr, xlen,
555 			(dh->dh_flags & SIDH_OUT)
556 				? BUS_DMASYNC_PREWRITE
557 				: BUS_DMASYNC_PREREAD);
558 
559 	/* success */
560 	sr->sr_dma_hand = dh;
561 
562 	return;
563 }
564 
565 
566 void
567 sw_dma_free(ncr_sc)
568 	struct ncr5380_softc *ncr_sc;
569 {
570 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
571 	struct sci_req *sr = ncr_sc->sc_current;
572 	struct sw_dma_handle *dh = sr->sr_dma_hand;
573 
574 #ifdef DIAGNOSTIC
575 	if (dh == NULL)
576 		panic("sw_dma_free: no DMA handle");
577 #endif
578 
579 	if (ncr_sc->sc_state & NCR_DOINGDMA)
580 		panic("sw_dma_free: free while in progress");
581 
582 	if (dh->dh_flags & SIDH_BUSY) {
583 		/* Give back the DVMA space. */
584 		bus_dmamap_sync(sc->sc_dmatag, dh->dh_dmamap,
585 				dh->dh_dvma, dh->dh_maplen,
586 				(dh->dh_flags & SIDH_OUT)
587 					? BUS_DMASYNC_POSTWRITE
588 					: BUS_DMASYNC_POSTREAD);
589 		bus_dmamap_unload(sc->sc_dmatag, dh->dh_dmamap);
590 		dh->dh_flags = 0;
591 	}
592 	sr->sr_dma_hand = NULL;
593 }
594 
595 
596 /*
597  * Poll (spin-wait) for DMA completion.
598  * Called right after xx_dma_start(), and
599  * xx_dma_stop() will be called next.
600  * Same for either VME or OBIO.
601  */
602 void
603 sw_dma_poll(ncr_sc)
604 	struct ncr5380_softc *ncr_sc;
605 {
606 	struct sci_req *sr = ncr_sc->sc_current;
607 	int tmo, csr_mask, csr;
608 
609 	/* Make sure DMA started successfully. */
610 	if (ncr_sc->sc_state & NCR_ABORTING)
611 		return;
612 
613 	csr_mask = SW_CSR_SBC_IP | SW_CSR_DMA_IP |
614 		SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR;
615 
616 	tmo = 50000;	/* X100 = 5 sec. */
617 	for (;;) {
618 		csr = SWREG_READ(ncr_sc, SWREG_CSR);
619 		if (csr & csr_mask)
620 			break;
621 		if (--tmo <= 0) {
622 			printf("%s: DMA timeout (while polling)\n",
623 			    ncr_sc->sc_dev.dv_xname);
624 			/* Indicate timeout as MI code would. */
625 			sr->sr_flags |= SR_OVERDUE;
626 			break;
627 		}
628 		delay(100);
629 	}
630 
631 #ifdef	DEBUG
632 	if (sw_debug) {
633 		printf("sw_dma_poll: done, csr=0x%x\n", csr);
634 	}
635 #endif
636 }
637 
638 
639 /*
640  * This is called when the bus is going idle,
641  * so we want to enable the SBC interrupts.
642  * That is controlled by the DMA enable!
643  * Who would have guessed!
644  * What a NASTY trick!
645  *
646  * XXX THIS MIGHT NOT WORK RIGHT!
647  */
648 void
649 sw_intr_on(ncr_sc)
650 	struct ncr5380_softc *ncr_sc;
651 {
652 	u_int32_t csr;
653 
654 	sw_dma_setup(ncr_sc);
655 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
656 	csr |= SW_CSR_DMA_EN;	/* XXX - this bit is for vme only?! */
657 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
658 }
659 
660 /*
661  * This is called when the bus is idle and we are
662  * about to start playing with the SBC chip.
663  *
664  * XXX THIS MIGHT NOT WORK RIGHT!
665  */
666 void
667 sw_intr_off(ncr_sc)
668 	struct ncr5380_softc *ncr_sc;
669 {
670 	u_int32_t csr;
671 
672 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
673 	csr &= ~SW_CSR_DMA_EN;
674 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
675 }
676 
677 
678 /*
679  * This function is called during the COMMAND or MSG_IN phase
680  * that precedes a DATA_IN or DATA_OUT phase, in case we need
681  * to setup the DMA engine before the bus enters a DATA phase.
682  *
683  * On the OBIO version we just clear the DMA count and address
684  * here (to make sure it stays idle) and do the real setup
685  * later, in dma_start.
686  */
687 void
688 sw_dma_setup(ncr_sc)
689 	struct ncr5380_softc *ncr_sc;
690 {
691 	u_int32_t csr;
692 
693 	/* No FIFO to reset on "sw". */
694 
695 	/* Set direction (assume recv here) */
696 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
697 	csr &= ~SW_CSR_SEND;
698 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
699 
700 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
701 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
702 }
703 
704 
705 void
706 sw_dma_start(ncr_sc)
707 	struct ncr5380_softc *ncr_sc;
708 {
709 	struct sw_softc *sc = (struct sw_softc *)ncr_sc;
710 	struct sci_req *sr = ncr_sc->sc_current;
711 	struct sw_dma_handle *dh = sr->sr_dma_hand;
712 	u_long dva;
713 	int xlen, adj, adjlen;
714 	u_int mode;
715 	u_int32_t csr;
716 
717 	/*
718 	 * Get the DVMA mapping for this segment.
719 	 */
720 	dva = (u_long)(dh->dh_dvma);
721 	if (dva & 1)
722 		panic("sw_dma_start: bad dva=0x%lx", dva);
723 
724 	xlen = ncr_sc->sc_datalen;
725 	xlen &= ~1;
726 	sc->sc_xlen = xlen;	/* XXX: or less... */
727 
728 #ifdef	DEBUG
729 	if (sw_debug & 2) {
730 		printf("sw_dma_start: dh=%p, dva=0x%lx, xlen=%d\n",
731 		    dh, dva, xlen);
732 	}
733 #endif
734 
735 	/*
736 	 * Set up the DMA controller.
737 	 * Note that (dh->dh_len < sc_datalen)
738 	 */
739 
740 	/* Set direction (send/recv) */
741 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
742 	if (dh->dh_flags & SIDH_OUT) {
743 		csr |= SW_CSR_SEND;
744 	} else {
745 		csr &= ~SW_CSR_SEND;
746 	}
747 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
748 
749 	/*
750 	 * The "sw" needs longword aligned transfers.  We
751 	 * detect a shortword aligned transfer here, and adjust the
752 	 * DMA transfer by 2 bytes.  These two bytes are read/written
753 	 * in PIO mode just before the DMA is started.
754 	 */
755 	adj = 0;
756 	if (dva & 2) {
757 		adj = 2;
758 #ifdef DEBUG
759 		if (sw_debug & 2)
760 			printf("sw_dma_start: adjusted up %d bytes\n", adj);
761 #endif
762 	}
763 
764 	/* We have to frob the address on the "sw". */
765 	dh->dh_startingpa = (dva | 0xF00000);
766 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, (u_int)(dh->dh_startingpa + adj));
767 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, xlen - adj);
768 
769 	/*
770 	 * Acknowledge the phase change.  (After DMA setup!)
771 	 * Put the SBIC into DMA mode, and start the transfer.
772 	 */
773 	if (dh->dh_flags & SIDH_OUT) {
774 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_OUT);
775 		if (adj) {
776 			adjlen = ncr5380_pio_out(ncr_sc, PHASE_DATA_OUT,
777 			    adj, dh->dh_addr);
778 			if (adjlen != adj)
779 				printf("%s: bad outgoing adj, %d != %d\n",
780 				    ncr_sc->sc_dev.dv_xname, adjlen, adj);
781 		}
782 		SCI_CLR_INTR(ncr_sc);
783 		NCR5380_WRITE(ncr_sc, sci_icmd, SCI_ICMD_DATA);
784 		mode = NCR5380_READ(ncr_sc, sci_mode);
785 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
786 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
787 		NCR5380_WRITE(ncr_sc, sci_dma_send, 0); 	/* start it */
788 	} else {
789 		NCR5380_WRITE(ncr_sc, sci_tcmd, PHASE_DATA_IN);
790 		if (adj) {
791 			adjlen = ncr5380_pio_in(ncr_sc, PHASE_DATA_IN,
792 			    adj, dh->dh_addr);
793 			if (adjlen != adj)
794 				printf("%s: bad incoming adj, %d != %d\n",
795 				    ncr_sc->sc_dev.dv_xname, adjlen, adj);
796 		}
797 		SCI_CLR_INTR(ncr_sc);
798 		NCR5380_WRITE(ncr_sc, sci_icmd, 0);
799 		mode = NCR5380_READ(ncr_sc, sci_mode);
800 		mode |= (SCI_MODE_DMA | SCI_MODE_DMA_IE);
801 		NCR5380_WRITE(ncr_sc, sci_mode, mode);
802 		NCR5380_WRITE(ncr_sc, sci_irecv, 0); 	/* start it */
803 	}
804 
805 	/* Let'er rip! */
806 	csr |= SW_CSR_DMA_EN;
807 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
808 
809 	ncr_sc->sc_state |= NCR_DOINGDMA;
810 
811 #ifdef	DEBUG
812 	if (sw_debug & 2) {
813 		printf("sw_dma_start: started, flags=0x%x\n",
814 		    ncr_sc->sc_state);
815 	}
816 #endif
817 }
818 
819 
820 void
821 sw_dma_eop(ncr_sc)
822 	struct ncr5380_softc *ncr_sc;
823 {
824 
825 	/* Not needed - DMA was stopped prior to examining sci_csr */
826 }
827 
828 #if (defined(DEBUG) || defined(DIAGNOSTIC)) && !defined(COUNT_SW_LEFTOVERS)
829 #define COUNT_SW_LEFTOVERS
830 #endif
831 #ifdef COUNT_SW_LEFTOVERS
832 /*
833  * Let's find out how often these occur.  Read these with DDB from time
834  * to time.
835  */
836 int	sw_3_leftover = 0;
837 int	sw_2_leftover = 0;
838 int	sw_1_leftover = 0;
839 int	sw_0_leftover = 0;
840 #endif
841 
842 void
843 sw_dma_stop(ncr_sc)
844 	struct ncr5380_softc *ncr_sc;
845 {
846 	struct sci_req *sr = ncr_sc->sc_current;
847 	struct sw_dma_handle *dh = sr->sr_dma_hand;
848 	int ntrans = 0, dva;
849 	u_int mode;
850 	u_int32_t csr;
851 
852 	if ((ncr_sc->sc_state & NCR_DOINGDMA) == 0) {
853 #ifdef	DEBUG
854 		printf("sw_dma_stop: DMA not running\n");
855 #endif
856 		return;
857 	}
858 	ncr_sc->sc_state &= ~NCR_DOINGDMA;
859 
860 	/* First, halt the DMA engine. */
861 	csr = SWREG_READ(ncr_sc, SWREG_CSR);
862 	csr &= ~SW_CSR_DMA_EN;
863 	SWREG_WRITE(ncr_sc, SWREG_CSR, csr);
864 
865 	/*
866 	 * XXX HARDWARE BUG!
867 	 * Apparently, some early 4/100 SCSI controllers had a hardware
868 	 * bug that caused the controller to do illegal memory access.
869 	 * We see this as SW_CSR_DMA_BUS_ERR (makes sense).  To work around
870 	 * this, we simply need to clean up after ourselves ... there will
871 	 * be as many as 3 bytes left over.  Since we clean up "left-over"
872 	 * bytes on every read anyway, we just continue to chug along
873 	 * if SW_CSR_DMA_BUS_ERR is asserted.  (This was probably worked
874 	 * around in hardware later with the "left-over byte" indicator
875 	 * in the VME controller.)
876 	 */
877 #if 0
878 	if (csr & (SW_CSR_DMA_CONFLICT | SW_CSR_DMA_BUS_ERR)) {
879 #else
880 	if (csr & (SW_CSR_DMA_CONFLICT)) {
881 #endif
882 		printf("sw: DMA error, csr=0x%x, reset\n", csr);
883 		sr->sr_xs->error = XS_DRIVER_STUFFUP;
884 		ncr_sc->sc_state |= NCR_ABORTING;
885 		sw_reset_adapter(ncr_sc);
886 	}
887 
888 	/* Note that timeout may have set the error flag. */
889 	if (ncr_sc->sc_state & NCR_ABORTING)
890 		goto out;
891 
892 	/*
893 	 * Now try to figure out how much actually transferred
894 	 *
895 	 * The "sw" doesn't have a FIFO or a bcr, so we've stored
896 	 * the starting PA of the transfer in the DMA handle,
897 	 * and subtract it from the ending PA left in the dma_addr
898 	 * register.
899 	 */
900 	dva = SWREG_READ(ncr_sc, SWREG_DMA_ADDR);
901 	ntrans = (dva - dh->dh_startingpa);
902 
903 #ifdef	DEBUG
904 	if (sw_debug & 2) {
905 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
906 	}
907 #endif
908 
909 	if (ntrans > ncr_sc->sc_datalen)
910 		panic("sw_dma_stop: excess transfer");
911 
912 	/* Adjust data pointer */
913 	ncr_sc->sc_dataptr += ntrans;
914 	ncr_sc->sc_datalen -= ntrans;
915 
916 	/*
917 	 * After a read, we may need to clean-up
918 	 * "Left-over bytes"  (yuck!)  The "sw" doesn't
919 	 * have a "left-over" indicator, so we have to so
920 	 * this no matter what.  Ick.
921 	 */
922 	if ((dh->dh_flags & SIDH_OUT) == 0) {
923 		char *cp = ncr_sc->sc_dataptr;
924 		u_int32_t bpr;
925 
926 		bpr = SWREG_READ(ncr_sc, SWREG_BPR);
927 
928 		switch (dva & 3) {
929 		case 3:
930 			cp[0] = (bpr & 0xff000000) >> 24;
931 			cp[1] = (bpr & 0x00ff0000) >> 16;
932 			cp[2] = (bpr & 0x0000ff00) >> 8;
933 #ifdef COUNT_SW_LEFTOVERS
934 			++sw_3_leftover;
935 #endif
936 			break;
937 
938 		case 2:
939 			cp[0] = (bpr & 0xff000000) >> 24;
940 			cp[1] = (bpr & 0x00ff0000) >> 16;
941 #ifdef COUNT_SW_LEFTOVERS
942 			++sw_2_leftover;
943 #endif
944 			break;
945 
946 		case 1:
947 			cp[0] = (bpr & 0xff000000) >> 24;
948 #ifdef COUNT_SW_LEFTOVERS
949 			++sw_1_leftover;
950 #endif
951 			break;
952 
953 #ifdef COUNT_SW_LEFTOVERS
954 		default:
955 			++sw_0_leftover;
956 			break;
957 #endif
958 		}
959 	}
960 
961  out:
962 	SWREG_WRITE(ncr_sc, SWREG_DMA_ADDR, 0);
963 	SWREG_WRITE(ncr_sc, SWREG_DMA_CNT, 0);
964 
965 	/* Put SBIC back in PIO mode. */
966 	mode = NCR5380_READ(ncr_sc, sci_mode);
967 	mode &= ~(SCI_MODE_DMA | SCI_MODE_DMA_IE);
968 	NCR5380_WRITE(ncr_sc, sci_mode, mode);
969 	NCR5380_WRITE(ncr_sc, sci_icmd, 0);
970 
971 #ifdef DEBUG
972 	if (sw_debug & 2) {
973 		printf("sw_dma_stop: ntrans=0x%x\n", ntrans);
974 	}
975 #endif
976 }
977